1. Field of the Invention
The present invention relates to a circular arc slide apparatus in which an upper plate (also referred to as a movable member) is able to be smoothly motioned in a circular arc along a circular arc track set in a motion reference plane perpendicular to a lower plate (also referred to as a base member).
2. Description of the Related Art
Circular arc slide apparatuses (also referred to as circular arc motion stages or simply as slide apparatuses) are used in laboratories or the like to precisely motion laboratory instruments and materials on which laboratory research is being undertaken and so on in a circular arc.
FIG. 29 shows a conventionally known circular arc slide apparatus (see, for example, Japanese Unexamined Patent Application No. 2005-3080).
This circular arc slide apparatus comprises a lower plate 510, an upper plate 520 assembled on the lower plate 510, and a circular arc track 530 provided between the lower plate 510 and the upper plate 520 for guiding the upper plate 520 in a circular arc motion in a motion reference plane perpendicular to the lower plate 510.
Separately manufactured guide rails 531 and 532 are mounted on mutually-opposing mounting surfaces of the lower plate 510 and the upper plate 520 respectively, two sets of opposing surfaces parallel with the aforementioned motion reference plane and mutually opposing in the direction orthogonal to the motion reference plane are assured in the lower plate 510 side guide rail 531 and the upper plate 520 side guide rail 532, and circular arc curve-shaped guide rails 533 of a sideways V-shape cross-section which by virtue of having respectively identical centers of curvature and radii of curvature constitute the aforementioned circular arc track are formed in these opposing surfaces. In addition, a plurality of rollers (columnar bodies) 535 serving as rolling bodies are rollably fitted by means of a cross-roller system into a space of a rectangular-shaped cross-section formed between the opposing guide rails 533, the roll of the rollers 535 guiding the upper plate 520 in a circular arc motion. The symbol 550 denotes a retainer for supporting the rollers 535, and the symbol 560 denotes a stopper screw adjusted to prevent fallout of the rollers 535 and the retainer 550.
However, there are problems inherent to the conventional circular arc slide apparatus shown in FIG. 29 in that, because the guide rails 531, 532 are separately manufactured to the lower plate 510 and the upper plate 520 before being assembled on the mounting surfaces of the lower plate 510 and the upper plate 520, error in the assembled sections prevents a sliding operation of satisfactory precision being performed, and the costs associated with the manufacture and assembly of the slide apparatus ensure the high cost thereof.
Thereupon, as shown in FIG. 30, a circular arc slide apparatus of a structure in which mutually-insertable guide rail portions 615, 625 are integrally formed and provided in a lower plate 610 and an upper plate 620 respectively, and in which circular arc curve-shaped guide grooves 633 of a sideways V-shape cross-section are formed directly on a mutually-opposing outer surface and inner surface of these guide rail portions 615, 625 and a plurality of rollers 635 supported by a retainer 650 are inserted into a space of a rectangular-shaped cross-section between the opposing guide rails 633 has been proposed with the object of resolving these problems (see, for example, Japanese Unexamined Patent Application No. 2005-3080). In this case as well, the rollers 635 are fitted by means of a cross-roller system (a system for arranging the axial center lines of adjacent rollers to intersect at right angles). The symbol 660 denotes a stopper screw.
When the guide grooves 633 are directly formed on the lower plate 610 and the upper plate 620 in this way, component part assembly error is eliminated and, accordingly, improved precision is achieved. In addition, the thus afforded reduction in the number of component parts contributes to cost reduction.
However, while the process of machining the structure shown in FIG. 29 is not that difficult due to the circular arc curve-shaped guide grooves 533 being machined in the guide rails 531, 532 which can be regarded as a single unit, because the structure shown in FIG. 30 necessitates that the guide grooves 633 of a sideways V-shape cross-section be directly formed in such a way as to describe a circular arc curve on the outer surface and the inner surface of the guide rail portions 615, 625 integrally formed in the lower plate 610 and the upper plate 620, in reality this machining is very difficult and, even if the machining were able to be performed, the exorbitant costs required to ensure high-precision machining was performed would remain a concern.